LED Lights Not Working

[gath2]

I have a JBJ Nano tank with this hood:
http://www.jbjnanocubes.com/contents...HOOD_ONLY.html

So I noticed about a month ago that on startup the lights would try to turn on the fans would kick on and then it would turn back off. It would do this several times before finally coming on solid. I took it apart and don't see anything wrong with the actual wiring. I noticed that 2 of the 5 LED light strips were not working at all as well. I swapped where they were plugged in on the pcb board to where one of the working and they still did not light up. I tested and I am getting power to the LED strip, but no light. Is it often that an entire strip will go out like this? If so where can I get a replacement or two in my case.

Anyway the problems have just gotten worse and worse to where now it just flashes trying to turn on. The fans don't even kick on and it will flash on and off for 5 - 10 minutes before finally coming on. What could be causing the flashing? Is it the driver? I'm thinking the flashing may have caused the LED's to go out, but I don't know enough about how it all works.

Does anyone have suggestions for where to get parts to fix this? I'm thinking just rebuilding everything might be my best bet at this point.

IMAG2618.jpg

IMAG2620.jpg

IMAG2621.jpg

IMAG2622.jpg

[gath2]

So no one know anything about these lights or what could cause these issues with LED lighting. I really can't afford to spend 250 on a new fixture. I've had no light on the tank for day snow and my corals are not happy.

[moatdaddy]

My opinion is first ask your local reef club if someone has lights you can borrow for a week while you figure out what to do. Next I would either rebuild or buy a new hood if you like the hood. Last time I had a nano was in 2004 and I hated it so much I never went back. So I personally would remove the hood and buy quality ati t5 if you can afford it. They grow great corals and hold their value. If your on a budget head over to eBay or amazon and buy Chinese LEDs. If you want LEDs and not budgeted read some reviews on kessils.

Also repost this in the DIY section. Title jbj LEDs need repair. Please help. Someone who builds LEDs may be able to have you text him photos of the layout and then offer advice. I'm not a led soldering guru. There are some here though.

Hope this helps.

[oreo57]

If the diodes are in series and no bypass diodes or resistors.. yes a whole strip can go out..
If you have a digital volt/ohm meter test each diode (meter set to ohms) by putting plus probe at plus and minus at minus AT the diode.. If the diode is good it will dimly light..

More than likely you have a few dead diodes. Since you are doing constant current..and the driver goes from 8-15v if only one diode is out you can bridge the diode to get the remaining ones to work.
There is a lot more going on in that thing then I can guess at (like the 5 voltage regulators.. fans???

BUT the main thing is to check each diode first.

[djbon]

I don't see any power supply modules powering the LM317S regulators. Possibly your power supply module is a goner. Or your LED beads are toasted, especially without any current limiting resistors visible on the LED strips. If it is constant voltage design, without current limiting resistor, LED beads will burnt quite easily.

[theatrus]

Looks like the LM317 might be used to add some safety to parallel the CC driver 5 ways. Not sure. Each string is only at 120ma, which is low, but if the parallel balance was lost ... with these cheap Chinese emitters who knows.

The flicker is a common symptom of a shorted output with the protection circuit in most power supplies.

[oreo57]

Originally Posted by djbon

I don't see any power supply modules powering the LM317S regulators. Possibly your power supply module is a goner. Or your LED beads are toasted, especially without any current limiting resistors visible on the LED strips. If it is constant voltage design, without current limiting resistor, LED beads will burnt quite easily.

Design is quite confusing..

24 Hour Light Cycles

Our new canopy offers around the clock illumination all powered by individual power cords
pg 6-7
http://www.drsfostersmith.com/Media/...cube-led-1.pdf

Daylight – 25 x 3 Watt – 14K
Dawn/Dusk – 4 x 3 Watt – Actinic/466nm
Moon – 2 x 1 Watt – Nite-Vu/456nm

The driver shown would "logically" be the one running the 4x3w chain.. That is what it is spec'd for..
does look like the 5 voltage regulators run the 5 series/parallel main strips.. moonlight ones???
a bit more digging and those run off a small transformer somewhere on a separate plug..
JBJ manual lists the 5 chips as "current regulators"..
I'm sure he will find a diode or 2 or 3 are burnt out.
HAVE to change my opinion on "bridging" across any burnt ones.

DON'T...

$2 worth of LEd's only $90
http://www.amazon.com/JBJ-NanoCube-R.../dp/B004XMZRH2

a bit more from the manual:
MT-601-13 Moon Light—Transformer
MT-601-14 Daylight—Remote Ballast
MT-601-15 Dawn/Dusk—Internal Ballast
Makes a bit more sense.. 2 moonlights external transformer.
Dawn/dusk corner chips.. constant current internal ballast
See pg 13
Daylight external "ballast" regulated internally w/ the " current limiting" chips..

ANYWAYS.. again.. just burnt out 3w chips.. Find cheap bridgelux replacements on e bay..remove dead ones..and thermal compound to center pad, solder new ones to board.
If you know any good electronics geeks they could reflow the whole board. Some of those lenses look pretty toasted..

[oreo57]

Originally Posted by theatrus

Looks like the LM317 might be used to add some safety to parallel the CC driver 5 ways. Not sure. Each string is only at 120ma, which is low, but if the parallel balance was lost ... with these cheap Chinese emitters who knows.

The flicker is a common symptom of a shorted output with the protection circuit in most power supplies.

see above it is more complicated than that.. besides only some chips are bad (well main problem) but they run off the same source.
In this case 3 power supplies. One for each type of chip.
moonlight off a wall wart.
"sunrise/sunset" (4 corner chips) off the built in cc driver (that may be what is "winking".)
Larger power brick running the 5x5 array using that on-board 5 chip regulator.
so each is powered "independent" at that point and he has swapped the strips. Same ones are dead regardless of position sooooo just bad strips seems to be the major problem..

Could be shorting temporarily and winking the bigger ps..

[theatrus]

Multiple power cords explains some of the crazy in this fixture - thanks for finding that . Looks like they just bolted together what they could find

[djbon]

Running LM317S as led driver will heat up the regulator. That thing must be toasted. I would rather run a constant voltage on LED in series with current limiting resistor.

[theatrus]

Originally Posted by djbon

Running LM317S as led driver will heat up the regulator. That thing must be toasted. I would rather run a constant voltage on LED in series with current limiting resistor.

Same power loss, just in the resistor. The LM317 idea is at least protected thermally and against extreme overcurrents.

I'm not saying its a good idea, just not the worst idea

[gath2]

Wow, this blew up since my last reply. Thanks for all the great info and suggestions for things to check.

My first goal was to find an alternate light source and I now have a 150w MH on it, so at least I have light again. That buys me some time to work on this and see what I can work out.

So it seems replacing the Diodes won't be too much of a problem once I find some replacements. JBJ wanted about the same price for the strip as Amazon and with two bad strips I would be better off with a whole new fixture, which seemed crazy. I'm pretty confident I can do this.

Consensus seems to be that the flickering is most likely a short somewhere. FYI this is only an issue with the daylight LEDS. I have noticed that if I leave it off for a long period of time it comes on for maybe a minute. Then the on off flickering starts and won't stay on for more than a second before going back off. That leads me to believe that it may be some sort of thermal protection in something.

Unfortunately, I won't have time to work on this tonight. Hopefully tomorrow evening after work I'll be able to pull it apart again to see what else I can find. Thanks for all the great info!

[oreo57]

That could be the power brick that runs the daylight "current regulators" if all strips do that.
If just one or two strips are out (or causing a problem) they will be the same ones regardless of where you plug them in (on the "current regulator" board).
If diodes are "shorted out" (unlikely) then removing the shorted strips will allow the daylights to run normally..
ANY numbers on the daylight power brick???

[gath2]

Yes all strips are going off as well as the fans. Whatever is causing the on/off flicker shuts everything down that plugs into that PCB board. Which is 4 fans and the 5 LED strips.

Two entire strips never come on at all no matter where I have them plugged in. The flickering originally would only happen a few times when they initially tried to come on. That is when I did my initial troubleshooting. I pulled it all apart and when everything was on and working I swapped the strips around and the two that were out would not come on no matter where they were plugged in. They were also receiving voltage across the diodes, so that lead me to believe the entire strip was out.

I'm not home to look at the power brick, which I'm assuming is the ballast.

This is the ballast on jbj's site:
http://www.jbjnanocubes.com/contents/en-us/p11017.html

It seems a new ballast is available from a 3rd party for $90
http://www.marineandreef.com/JBJ_28G...Z7gaAtdo8P8HAQ

I'll get more info on it when I get home. I let it try to turn on for about 30 minutes last night and it never would stay on except for the first 30-60 seconds after being off for some time.

Obviously I need to figure out the cause and get the rest of the unit to work before I begin trying to replace the bad diodes on the two strips.

[bjolly]

I have the same hood, about 5 years old, and all but one strip is out. I looked into getting it repaired and jbj advised I should just replace the whole thing since most of it is not working. The advice I got by asking around is that a lot of people have had trouble with the hood and that I could get an LED fixture to retrofit into it for much less $. Nanoboxreef was what was recommended to me. FWIW.

[oreo57]

Originally Posted by gath2

Yes all strips are going off as well as the fans. Whatever is causing the on/off flicker shuts everything down that plugs into that PCB board. Which is 4 fans and the 5 LED strips.

Yea that sounds like the "ballast"..
looks to be nothing more than a 24V switching power supply....Need the amp rating. Should cost no more than $30 to replace, but would need to add plug..

Originally Posted by bjolly

I have the same hood, about 5 years old, and all but one strip is out.

e-bay bridgelux chips and a soldering iron and thermal compound and all those could be rebuilt for under $20 easily.

[bjolly]

yeah, I had a feeling it wouldnt be hard to fix - if only I had a soldering iron, the necessary parts, and the slightest clue how to use them. Unfortunately I'm hopeless at DIY. The message I took home from it was that the original hood isn't a great design, so not worth buying a whole new one the same.

[gath2]

Here is the Ballast.

Seems to be 24V with 4.16 Amp. I sure like the idea of finding a cheaper one and just replacing the cord. I'm going to do some searching to see what good old Google comes up with.

[gath2]

I've obviously not done much research into how LED's actually work. The driver that I originally took a picture of appears to be running the 4 dawn/dusk LED's, which has a straight 110 plug for the wall. This is the internal ballast in the manual.
MT-601-15 Dawn/Dusk—Internal Ballast

Am I correct that in this fixture the Power Supply and Drive are one and the same? This is the remote ballast that the manual refers to. I'm also assuming the chips on the PCB board that the Daylight LED's and fans plug into is distributing the power from the driver.
MT-601-14 Daylight—Remote Ballast

So should I actually be looking for a driver? There are a lot of options and price range when just looking at the V/A drivers. Ones marked as class2 seem to be more expensive and look like they are built better. I need to look closer at how the driver is wired in the hood to see what kind of wires I need coming out of a new one.

[gath2]

Just wanted to give everyone that's offered opinions and help an update. I had a little bit of time to mess with my hood last night and pulled it all apart. I was working on this in the garage which is very cool right now and the lights were staying on for 10-30 seconds at a time before going off. Unlike the every second or so when it was last on the tank. Still leaves me to believe something is overheating causing it to quit.

I removed the two bad LED strips from the system and saw no change, so I don't think there is any sort of short at least from these causing the issue.

I found a thermostat that screwed into the underside of the heatsink. I believe it's basically just a thermal fuse and if it overheats it would stop working all together and have to be replaced. I bypassed it with the wiring and it didn't seem to make any difference in the lights going on and off. So it's not that.

My last shot was to actually look inside the ballast. It's completely filled with some sort of hard resin. My guess is to keep everything dry since it's used near an aquarium. So I'm not going to be able to do anything with that and I'm off to look for a new PSU.

There seems to be a wide range of price and design of led drivers that have the same power specs. What exactly do I need to look for?

This one is the cheapest I found, but has an IP rating of 20 and doesn't look like it would do well near moisture:
http://www.amazon.com/SANPU-120-24V-.../dp/B00SMLUFU4

This one has an IP 67 and looks much more suitable for my environment.
https://www.1000bulbs.com/product/17...6a0aAk_j8P8HAQ

Am I missing something here or need to look somewhere else?

[gath2]

I may have jumped the gun since I don't have a power supply yet, but I purchased my LED's. Figured they might take awhile to get here so I should order sooner than later.

Anyone have any advice or answers to my questions on the driver I should purchase?

[theatrus]

How many LEDs are you needing to put in series? Single channel?

[gath2]

I'm hoping to keep the hood wired exactly the same as it is currently. My current PSU is 24V with 4.16 Amp. but doesn't show any kind of wattage that I can tell. It hooks up to a PCB, which turns on 5 strips of 5 x 3w LED's in series as well as 4 fans. A new remote ballast made for this hood is going to be $97 shipped to my door.

oreo57

suggested I should be able to find an alternative and wire it myself for much less.

[gath2]

Just to give everyone that was kind enough to offer advice an update, my new power supply arrived. I ended up getting one made for my light for about $85. Figured it was worth the extra $30 to be sure it worked. Lights stay on all the time, so no more off and on! My new LED lights also arrived, so now I just need to get to soldering them on to the two burned out. So happy to get my light back and lose the hot MH light that is on it now.

[oreo57]

Good to see you got it all sorted out..